Apparatus for electrochemical waste treatment via electroflocculation is known, such as from DE-A-4416973. The apparatus disclosed thereinessentially consists of a reactor housing, which is closed at its upper side, in horizontally inclined arrangement containing upright plate- or sword-shaped electrode sheets of a width-length ratio of less than one. The waste water is pumped through this reactor in the main direction of the longitudinal reactor axis and leaves the same via an overflow weir at its upper front. At the same time, a stream of gas is introduced into the lower side of the reactor, which is preferably fed by exhaust air from the pneumatically operated waste water circulation pump.
As compared to other known apparatus for electroflocculation, the apparatus known from DE-A-4416973 possesses the following improvements:
easy, i.e. energy-saving, insertion and replacement of the electrodes; PA1 easy removal of the built-up electrode sludge through the lower end of the reactor housing due to use of the force of gravity; PA1 inhibition of foaming in the reactor; PA1 safety from oxyhydrogen gas explosions.
These and other known apparatuses for electroflocculation have the deficiency that the metal oxide layers of little electrical conductivity can build up on the anode surfaces and considerably impede the passage of electric current. These layers may also lead to short circuits due to bridge formation between the electrodes and therefore to an interruption of the electrolytic process.